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Chemistry : asked on c4dcbd4f583b26716b74e02675d2e850
 09.02.2021

Which of the following pairs of reactants would produce hydrogen most slowly?

 

A. Magnesium powder and 4 mol l-1 acid

B. Magnesium powder and 2 mol l-1 acid

C. Magnesium ribbon and 4 mol l-1 acid

D. Magnesium ribbon and 2 mol l-1 acid


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07.11.2022, solved by verified expert
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Ranjana Bhatt
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we know that, rate of a reaction is directly proportional to the surface area. so in magnesium powder there is large surface area as compared to the magnesium ribbon. therefore magnesium powder reacts rapidly and more.

we know that, rate of a reaction is directly proportional to the surface area. so in magnesium powder there is large surface area as compared to the magnesium ribbon. therefore magnesium powder reacts rapidly and more.

Option  b is correct because here the acid is diluted so it will reacts.slowly and less hydrogen gas will be formed.

Like Mg+2 hcl ----> MgCl2 + H2 ( if acid is Hydrochloric acid)

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